1. Field of the Invention
The present invention relates to an optical disk, an optical disk barcode forming method, an optical disk reproduction apparatus, a marking forming apparatus, a method of forming a laser marking on an optical disk, and a method of manufacturing an optical disk.
2. Related Art of the Invention
In the manufacturing process of optical disks, it has been commonly practiced to record a serial number, lot number, etc. on each optical disk in the form of a barcode.
Since such information cannot be written to a pit information area of the optical disk, it has been practiced to write the barcoded information to a non-information area, or unused space, on the optical disk.
When reproducing (playing back) such an optical disk, the pit information is read by an optical pickup; to read the barcoded information such as a serial number, etc. recorded in the non-information area, however, a separate reading device has been used.
In the above prior art optical disk, since information carrying a serial number and the like is not recorded in a pit area but recorded in a non-information area, as described above, a separate reading device has had to be provided in addition to the usual optical pickup, the resulting problem being increased complexity of the playback apparatus construction.
In view of the above problem with the prior art, it is an object of the present invention to provide an optical disk wherein data such as a disk ID number, etc. is converted into a barcode and recorded in a pit area in overwriting fashion, thereby permitting the use of a single optical pickup to read both the bit data and barcode data. It is another object of the invention to provide a barcode forming method, etc. for such an optical disk.
One aspect of the invention is an optical disk on which data is recorded with CLV, wherein, in a prescribed region of a pre-pit signal area on said disk, all or part of a barcode is written in overwriting fashion by selectively removing a reflective film in said prescribed region.
Another aspect of the invention is an optical disk, wherein a control data area is provided for holding therein physical feature information concerning said optical disk, and an identifier for indicating the presence or absence of said barcode is recorded in said control data area.
Still another aspect of the invention is an optical disk, wherein a guard-band area where no data is recorded is provided between said control data area and said prescribed region of said pre-pit signal area.
Yet another aspect of the invention is an optical disk, wherein said barcode is formed in such a manner that two or more barcode signals cannot occur within one prescribed time slot.
Still yet another aspect of the invention is an optical disk, wherein said barcode contains data at least including ID information uniquely given to said optical disk.
A further aspect of the invention is an optical disk, wherein said barcode contains data including, in addition to said ID information, a public key of a public key encryption function corresponding to said ID information, said public key being used when encrypting prescribed data for transmission to an external party in order to obtain from said external party a password required to reproduce said optical disk.
A still further aspect of the invention is an optical disk, wherein said ID information is encrypted or applied a digital signature to.
A yet further aspect of the invention is an optical disk, wherein a secret key of a public key encryption function is used when applying encryption or a digital signature to said ID information.
A still yet further aspect of the invention is an optical disk, wherein said optical disk is constructed from two disk-substrates laminated together.
One aspect of the invention is an optical disk barcode forming method wherein pulsed laser light from a light source is made into a rectangular beam pattern by using a rectangular mask and said rectangular beam pattern is focused on a reflective film in a pre-pit signal region in a prescribed radius portion of an optical disk on which data is recorded, and at the same time, said optical disk is rotated, thereby forming a plurality of rectangular reflective-film-removed regions as a barcode in the same radius portion on said reflective film.
Another aspect of the invention is an optical disk barcode forming method, wherein said optical disk includes a control data area for holding therein physical feature information concerning said optical disk, and an identifier for indicating the presence or absence of said barcode is recorded in said control data area.
Still another aspect of the invention is an optical disk barcode forming method, wherein said barcode is formed in such a manner that two or more barcode signals cannot occur within one prescribed time slot.
Yet another aspect of the invention is an optical disk barcode forming method, wherein said optical disk is constructed from two disk-substrates laminated together.
Still yet another aspect of the invention is an optical disk reproduction apparatus wherein recorded contents of a main data recording area, recorded by forming pits on an optical disk, are reproduced by using a rotational phase control for a motor, while recorded contents of a different recording area than said main data recording area, recorded by selectively forming low-reflectivity portions on a reflective film in said different recording area, are reproduced by using rotational speed control for said motor, and
A further aspect of the invention is an optical disk reproduction apparatus, wherein tracking control is not performed in said different recording area.
A still further aspect of the invention is an optical disk reproduction apparatus, wherein tracking control is, in effect, performed in said different recording area.
A yet further aspect of the invention is an optical disk reproduction apparatus, wherein a rotational speed is the rotational speed that would be achieved in said different recording area is said rotational phase control were applied.
A still further aspect of the invention is an optical disk reproduction apparatus, wherein the rotational speed of said motor in aid rotational speed control is maintained at a prescribed value based on a result obtained by measuring a minimum-length pit in said different recording area.
A yet further aspect of the invention is an optical disk reproduction apparatus, wherein said low-reflectivity portions are a barcode formed by selectively removing said reflective film.
A still yet further aspect of the invention is an optical disk reproduction apparatus wherein
said low-reflectivity portions are a barcode, said different recording area is also such area to which contents are recorded with pits, and
when reproducing the recorded contents of said different recording area, a high-frequency-component signal generated during reproduction of said pits which are formed in said different recording area is reduced or eliminated by a low-pass filter, thereby making it possible to separate a signal which is reproduced from said barcode.
One aspect of the invention is an optical disk reproduction apparatus, wherein
said low-reflectivity portions are a barcode, and
when reproducing the recorded contents of said different recording area, the width of a signal obtained by reading said barcode is increased to a prescribed width and then measured with sampling pulses from a control section.
Another aspect of the invention is an optical disk reproduction apparatus, wherein said optical disk is constructed from two disk-substrates laminated together.
Still another aspect of the invention is an optical disk reproduction apparatus, wherein said optical disk includes a control data area for holding therein physical feature information concerning said optical disk, and an identifier for indicating the presence or absence of said barcode is recorded in said control data area.
Yet another aspect of the invention is an optical disk reproduction apparatus, wherein, after reading recorded contents of said control data area and judging the presence or absence of said barcode, it is determined whether an optical pickup should be moved to an inner portion or an outer portion of said optical disk.
Still yet another aspect of the invention is a marking forming apparatus which comprises:
marking forming means for applying a marking on a reflective film formed on a disk;
marking position detecting means for detecting a position of said marking; and
position information writing means for converting at least said detected position information or information concerning said position information into a barcode, and for selectively removing said reflective film to write said barcode to an optical disk on which data is recorded with CLV,
wherein all or part of said barcode is written in overwriting fashion to a prescribed region of a pre-pit signal area on said optical disk.
A further aspect of the invention is a marking forming apparatus, wherein said disk is constructed from two disk-substrates laminated together.
A still further aspect of the invention is a marking forming means, wherein said position information writing means includes encrypting means for encrypting at least said detected position information or information concerning said position information, and writes contents thus encrypted to said disk.
A yet further aspect of the invention is a marking forming apparatus, wherein said position information writing means includes digital signature means for applying a digital signature to at least said detected position information or information concerning said position information.
and the writing at least said detected position information or information concerning said position information means writing information concerning a result of said digital signature application to said disk.
A still yet further aspect of the invention is a reproduction apparatus which comprises:
position information reading means for reading position information of a marking or information concerning said position information, said position information or said information being formed by (1) applying a marking on a reflective film formed on a disk, (2) detecting position of the marking, (3) converting detected said position information or said information into a barcode, and (4) writing the barcode with selectively removing said reflective film on said optical disk on which data is recorded with CLV;
marking reading means for reading information concerning a physical position of said marking;
comparing/judging means for performing comparison and judgement by using a result of reading by said position information reading means and a result of reading by said marking reading means; and
reproducing means for reproducing data recorded on said optical disk in accordance with a result of the comparison and judgement performed by said comparing/judging means,
wherein all or part of said barcode is written in overwriting fashion to a prescribed region of a pre-pit signal area on said optical disk.
One aspect of the invention is a reproduction apparatus according, wherein at least said detected position information or information concerning said position information is written to said disk by position information writing means.
Another aspect of the invention is a reproduction apparatus, wherein
said position information writing means includes encrypting means for encrypting at least said detected position information or information concerning said position information, and
said position information reading means includes decrypting means corresponding to said encrypting means, and by using said decrypting means, decrypts said encrypted position information or information concerning said position information.
Still another aspect of the invention is a reproduction apparatus, wherein:
said position information writing means includes digital signature means for applying a digital signature to at least said detected position information or information concerning said position information, and writes information concerning a result of said digital signature application to said disk,
and said position information reading means includes
authenticating means corresponding to said digital signature means, and
position information extracting means for obtaining said position information from an authentication process performed by said authenticating means and/or from said information concerning the result of said digital signature application,
when an output indicating correctness of said authentication result is produced from said authenticating means, said comparing/judging means performs the comparison and judgement by using the position information obtained by said position information extracting means and the result of reading by said marking reading means, and when said output indicating correctness is not produced, the reproduction is not performed.
Yet another aspect of the invention is a method of manufacturing a disk, which comprises the steps of:
forming at least one disk;
forming a reflective film to said formed disk;
applying at least one marking to-said reflective film;
detecting at least one position of said marking; and
encrypting said detected position information and writing said encrypted information onto said disk,
wherein, when encrypting and writing, at least said encrypted information is converted into a barcode, and said barcode is written by selectively removing said reflective film on said disk on which data is recorded with CLV, and all or part of said barcode is written in overwriting fashion to a prescribed region of a pre-pit signal area on said disk.
Still yet another aspect of the invention is a method of manufacturing a disk, which comprises the steps of:
forming at least one disk;
forming a reflective film to said formed disk;
applying at least one marking to said reflective film;
detecting at least one position of said marking; and
applying a digital signature to said detected position information and writing onto said disk,
wherein, when applying said digital signature and writing, at least a result of said digital signature is converted into a barcode, and said barcode is written by selectively removing said reflective film on said disk on which data is recorded with CLV, all or part of said barcode being written in overwriting fashion to a prescribed region of a pre-pit signal area on said disk.
A further aspect of the invention is a disk wherein a marking is formed by a laser to reflective film of said disk holding data written thereon, at least position information of said marking or information concerning said position information is encrypted or applied a digital signature, at least said encrypted information or digital signature-appended information is converted into a barcode, and said barcode is written by selectively removing said reflective film on said disk on which data is recorded with CLV, all or part of said barcode being written in overwriting fashion to a prescribed region of a pre-pit signal area on said disk.